Fatal error: Uncaught Error: Interface "Symfony\Component\Serializer\Mapping\Loader\LoaderInterface" not found in /home/zdpktgd/ptc/vendor.old/symfony/serializer/Mapping/Loader/AttributeLoader.php:34 Stack trace: #0 {main} thrown in /home/zdpktgd/ptc/vendor.old/symfony/serializer/Mapping/Loader/AttributeLoader.php on line 34